• Progress in Medical Physics
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• v.27 no.2
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• pp.64-71
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• 2016

We develop a manufacture procedure for the production of a patient specific customized bolus (PSCB) using a 3D printer (3DP). The dosimetric accuracy of the 3D-PSCB is evaluated for electron beam therapy. In order to cover the required planning target volume (PTV), we select the proper electron beam energy and the field size through initial dose calculation using a treatment planning system. The PSCB is delineated based on the initial dose distribution. The dose calculation is repeated after applying the PSCB. We iteratively fine-tune the PSCB shape until the plan quality is sufficient to meet the required clinical criteria. Then the contour data of the PSCB is transferred to an in-house conversion software through the DICOMRT protocol. This contour data is converted into the 3DP data format, STereoLithography data format and then printed using a 3DP. Two virtual patients, having concave and convex shapes, were generated with a virtual PTV and an organ at risk (OAR). Then, two corresponding electron treatment plans with and without a PSCB were generated to evaluate the dosimetric effect of the PSCB. The dosimetric characteristics and dose volume histograms for the PTV and OAR are compared in both plans. Film dosimetry is performed to verify the dosimetric accuracy of the 3D-PSCB. The calculated planar dose distribution is compared to that measured using film dosimetry taken from the beam central axis. We compare the percent depth dose curve and gamma analysis (the dose difference is 3%, and the distance to agreement is 3 mm) results. No significant difference in the PTV dose is observed in the plan with the PSCB compared to that without the PSCB. The maximum, minimum, and mean doses of the OAR in the plan with the PSCB were significantly reduced by 9.7%, 36.6%, and 28.3%, respectively, compared to those in the plan without the PSCB. By applying the PSCB, the OAR volumes receiving 90% and 80% of the prescribed dose were reduced from $14.40cm^3$ to $0.1cm^3$ and from $42.6cm^3$ to $3.7cm^3$, respectively, in comparison to that without using the PSCB. The gamma pass rates of the concave and convex plans were 95% and 98%, respectively. A new procedure of the fabrication of a PSCB is developed using a 3DP. We confirm the usefulness and dosimetric accuracy of the 3D-PSCB for the clinical use. Thus, rapidly advancing 3DP technology is able to ease and expand clinical implementation of the PSCB.

• Journal of the Korean Society of Propulsion Engineers
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• v.2 no.2
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• pp.64-73
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• 1998

In twin spool aero-engine, there may be a S shaped annular duct between high pressure and low pressure spools. The flow passing this S shaped duct experiences the flow acceleration and deceleration due to the convex and concave surface of the duct as well as the increase of blockage according to the boundary layer growth along the surfaces. So, the high pressure compressor which is located behind the S shaped duct is influenced by the non-uniform flow field generated by the geometry of inlet duct. To study the influence of the S shaped duct on the centrifugal stage, performance tests were implemented for the compressor with straight cylindrical inlet duct and with S shaped inlet duct, respectively. The test results showed that the performance, such as pressure ratio and efficiency, of the compressor with S shaped duct was worse than that of the compressor with cylindrical duct. And the compressor with S shaped duct had reduced maximum flow rate around design speed. To investigate the cause of performance degradation, flow anlaysis was performed for the impeller in front of which is located S shaped annular duct. The result of CFD showed the strong acceleration of the flow in the axial direction around the inducer tip region which caused the increase of relative mach number and the decrease of incidence angle of the flow.

• Journal of Life Science
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• v.8 no.5
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• pp.582-588
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• 1998

The male reproductive system of Macrobrachium nipponense consists of a pair of lobulate testes enveloped within a mesenteric sheath extending the length of the carapace. The paired vasa deferentia originated from the mid-lateral region of each testis and extended to the genital pores at the base of the fifth walking legs. The vas deferens has four morphologically distinct regions, i.e., a short and slender proximal region, a long convoluted region, an elongate distal region and an ejaculatory duct that terminates at the genital pore. The sperm mass produced in the testes is surrounded by a basophilic matrix adjacent to the high columnar epithelium and an eosinophilic matrix adjacent to the simple columnar epithelium. The sperm cord is stored in the ejaculatory duct until it is ejaculated. Androgenic gland is found near the subterminal region of the ejaculatory duct between the muscles of the coxopodite of the last thoracic leg. The cell of the androgenic gland is about 6~8 $\mu$m in length, characterized by with extended chromatin in the large nucleus that stained weakly with hematoxylin and there is a large quantity of cytoplasm. The sperm of M. nipponense are typical of the palaemonid type, having a convex, cup shaped head and an elongated spike extending from the centre of the convex head. The spermatophore consisted of an eosinophilic matrix, a basophilic matrix and paired sperm masses which was surrounded by the basophilic matrix. It generally shows a bilaterally symmetrical structure.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.25 no.5
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• pp.475-482
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• 2007

Most golfers believe that knowing yardages will improve their score. Certainly it helps with club selection. But, simple "Graphic" yardage guides being notorious for error and inaccuracies, which a serious golfer will pick immediately, only serve to erode the players enjoyment and ultimately, golf course satisfaction. Someone believes with low-level aerial photographic images, golfer will be impressed with the accuracy of the depiction, helping them play a more confident game. But, there are no mapping products in true 3-D available in the world that allows a golfer to determine shot distances in yards or meters. So, we suggest an lenticular technology for real 3-D display as a viable alternative to conventional image map solution. This technology is an image display method for the generation of multi-image effects like 3D visualization or animation. This methodology is cutting edge stereoscopic image which overcomes the limitation of conventional photo tech by recomposing and producing 3 dimensional images. A significant strength of this methods its versatility concerning display effects. The main use of the hardcopy 3-D lenticular displays is in the fields of science, education, planning, and representation. This paper gives a concise overview of the lenticular foil technology and describes the production of the true 3-D yardage book of golf courses. For this study, 3-D effects are achieved and evaluated with the lenticular display by incorporation multiple synthetic images based on digital topographic terrain model and by using the two images of the actual stereopair.

• The Korean Journal of Mycology
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• v.37 no.1
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• pp.19-27
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• 2009

This study was conducted to investigate genetic characteristics of 25 Pleurotus eringii strains that have been released in Korea based on cultural, morphological features and PCR fingerprints. Strains PER-007 and PER-012 showed distinct cultural characteristics in growth rate, morphological characteristics of mycelial colony and fruiting bodies when compared to those of other strains. Strain PER-007 did not form primordium initiation in sawdust medium and PER-012 also showed different phenotypes on fruiting bodies. Eleven URP primers were used to detect PCR polymophic bands in P. eringii strains. Primers URP1F, URP2R, URP2F, URP4R, URP6R, URP9F and URP17R were selected as useful primers for amplifying PCR polymorphic bands in P. eringii strains. The genetic similarity index was calculated by using PCR polymorphic bands amplified by eight URP primers among the 25 strains. The P. eringii strains were grouped by four distinct clusters on the UPGMA analysis. The genetic similarity values ranged from 100% to 76% were observed in three major groups, suggesting close genetic relatedness of them. Exceptionally, PER-007 and PER-017 were involved in outgroup.

• Restorative Dentistry and Endodontics
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• v.33 no.4
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• pp.323-331
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• 2008

Flexibility and fracture properties determine the performance of NiTi rotary instruments. The purpose of this study was to evaluate how geometrical differences between three NiTi instruments affect the deformation and stress distributions under bending and torsional conditions using finite element analysis. Three NiTi files (ProFile .06 / #30, F3 of ProTaper and ProTaper Universal) were scanned using a Micro-CT. The obtained structural geometries were meshed with linear, eight-noded hexahedral elements. The mechanical behavior (deformation and von Mises equivalent stress) of the three endodontic instruments were analyzed under four bending and rotational conditions using ABAQUS finite element analysis software. The nonlinear mechanical behavior of the NiTi was taken into account. The U-shaped cross sectional geometry of ProFile showed the highest flexibility of the three file models. The ProTaper, which has a convex triangular cross-section, was the most stiff file model. For the same deflection, the ProTaper required more force to reach the same deflection as the other models, and needed more torque than other models for the same amount of rotation. The highest von Mises stress value was found at the groove area in the cross-section of the ProTaper Universal. Under torsion, all files showed highest stresses at their groove area. The ProFile showed highest von Mises stress value under the same torsional moment while the ProTaper Universal showed the highest value under same rotational angle.

• Journal of The Geomorphological Association of Korea
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• v.18 no.4
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• pp.1-15
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• 2011

This work is to review the granite landforms studies by Korean geographers. It is verified that geomorphlogical characteristics of granite present landscapes characterized by 1) in case of mountains, are difficultly or irregularly weathered, so as to develop rocky forms such as domes, cliffs, and tors ; 2) in case of stream valley that is inter-massif lowland, low relief hills and flood plains with alluvium. All these facts owe to the difference of weathering mode granite properties. The granite hills and alluvial plains of southwestern coastal parts in Korean peninsula is low undulatory and large owing not only to the existence of highly weathered granitic regolith, but also to frequent flooding. Cultivated brownish field, orchard, meadow and forest are located at granite hills. On the other hand paddy rice field at granite alluvial plains. Korean peninsula have endured erodible geomorphlogical processes since Miocene when warping it up. Therefore many intermontane basins are located on the weathered granite areas which are surrounded by mountains composed of much less Precambrian gneiss complex. In fact, intermontane basin is mainly linear fault-line valley. The landforms of the intermontane basins are characterized by gentle piedmont slopes, alluvial fans, fluvial terraces and alluvial plains.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.37 no.3
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• pp.93-107
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• 2019

The purpose of this paper is to explore the application of Chinese traditional garden space construction principle studied by predecessors in modern park landscape, and to find more methods of traditional garden space construction inheritance and innovation through research. Tian Chaoyang's book "Fifteen Lectures on Chinese Classical Gardens and Modern Translation" mentions that Chinese traditional gardens are combining time and space, so he draws a brief pattern diagram containing the principle of the space construction. According to this principle of space construction, the researchers chose Qujiang Pool Heritage Park, which combines modern and traditional, then analyzed its spatial structure and and space elements. The results are as follows. The complex spatial structure of the park is composed of spatial boundary lines and spatial routes. The complex boundary space is composed of bridges, squares, plants, rows of buildings and other elements. The water space in the center of the park is designed in accordance with the traces of the historical water system, and its natural zigzag shoreline expands the water space. The central water space is divided into the big pool and the small pool, the Yanbo island and Bird island are created respectively. The building at the park boundary connects the park's interior and exterior. Most of the buildings in the park are located in the convex corner of the route or space. Through this research, it can be concluded that Qujiang park also applies the space construction principle combining time and space. And then, the garden elements of Qujiang park are recreating the history and culture of Qin, Han, Sui and Tang dynasties with modern methods, thus creating a park with Chinese regional characteristics. Since the Tang dynasty was the most prosperous period in Qujiang, the park was dominated by Tang culture. Through the research of this paper, we can see that the space construction principle of Qujiang Pool Heritage Park is the inheritance of the space construction principle of Chinese traditional garden. And the landscape element of Qujiang park is the landscape created by combining traditional history and culture, which is the innovative part of modern garden. Through this study, the creation of modern landscape with Chinese characteristics can provide some hints on the direction of inheritance and innovation.

• Applied Microscopy
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• v.37 no.2
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• pp.83-91
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• 2007

The present study examined the epidermal changes of adhesive disks which occur during attachment in Parthenocissus tricuspidata using scanning and transmission electron microscopy. Several adhesive disks, each covered with a bract, develop from the shoot apical meristem during early development. In the initial stage, the adhesive disks are club-shaped and their upper and lower epidermis are indistinguishable. However, in the actively growing stage, they become spherical and both epidermis are clearly differentiated into the adventitious roots. Prior to wall attachment, the adhesive disks exhibit adaxial convex and abaxial concave shapes, and electron-dense substances are abundant in the vacuoles of epidermal cells. The peripheral area of the adhesive disk is adhered first to the wall surface, while the central area is drawn inward in a vacuum-like state during attachment. As the attachment progresses and the electron-dense substances continue to discharge, the upper and lower epidermis rapidly undergo deterioration and the disks shrink considerably. At this stage, structural changes of the lower epidermis occur much faster than in the upper one. The discharged substance is accumulated on the wall surface, and this aids the attachment of adhesive disks on the wall for long periods. In this manner, the shape and structure of the adhesive disk epidermis change drastically from initial growth to the mature stage. Further, the role of electron-dense substance and shrinkage of the disk during attachment has been discussed in Parthenocissus tricuspidata.

• Korean Journal of Mineralogy and Petrology
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• v.33 no.4
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• pp.349-359
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• 2020

The Ulsan Fault Zone (UFZ) of NNW trend is developed in the Gyeongsang Basin, the southeastern part of the Korean Peninsula, and the Quaternary faults have been found around the UFZ. The faults generally thrust the Bulguksa igneous rocks of Late Cretaceous-Early Tertiary upon the Quaternary deposits or are developed within the Quaternary deposits. They mainly show the reverse-slip sense of top-to-the west movement. The lines connecting the their outcrop sites show a zigzag-form which is similar to the orientation of their fault surfaces which show the various trends, like (W)NW, N-S, (E)NE, ENE trends. The E-W trending dextral strike(-slip) fault is found in the Quaternary deposits of the Singye-ri valley. It cuts the N-S trending reverse fault and are cut by the N-S trending thrust fault again. Two types of at least two times of Quaternary tectonic movements related to the formation of neotectonic fault zone in the Singye-ri valley are considered from such the geometric and kinematic characteristics of Quaternary faults. One is the reverse faulting of N-S trend by the E-W directed 1st compression and associated the strike-slip tear faulting of E-W trend, and then the thrust faulting of N-S trend by the E-W directed 2nd compression. The other is the reverse faulting of N-S trend, and then the dextral strike-slip faulting of E-W trend by the NW-SE directed compression, and then the thrust faulting of N-S trend. In this paper is suggested the development history of Singye-ri neotectonic fault zone on the basis of the various orientations of Quaternary fault surfaces around the UFZ, and the zigzag-form connecting line of their outcrop sites, and the compressive arc-shaped lineaments which convex to the west reported recently in the Yangsan Fault Zone.